A new acoustical/optical translator can extend the imaging capability of an available 3D optical holographic system to signals comprised of pressure waves (ultrasound). In analogy with electromagnetic waves, properly recorded sonic waves produce a holographic pattern which, if appropriately processed, enable the reconstruction of the image of the sonically irradiated object. Since both detection and reconstruction can be accomplished with visible radiation, this technique for the conversion of the sonic information to an optical signal, serves as the key element enabling the optical technology to be directly utilized. Estimates indicate that submillimeter spatial resolution is achievable. Specific applications are seen for quantitative measurement of cardiac function and malignant tumor detection and treatment. The objective of the Phase I program is the experimental demonstration of the concept underlying the new acoustical/optical translator, the key improvisation enabling the system to use acoustic data. This includes the construction and test of the translator and the comparison of its properties with theoretical values. The performance of these tasks will permit the formulation of a Phase II Work Plan leading to the construction of an ultrasonic instrument capable of producing rotatable 3D images of in vivo organs and tissues with submillimeter spatial resolution.